With the development of LED technology, LED has been widely used in more and more technical fields due to its superior performance. For example, various existing display devices adopt LED as an illuminating source. Specifically, for example, LED is used as a backlight source.
FIG. 1 illustrates an existing LED packaging structure. This LED packaging structure includes a support 1 having a cavity; a metal layer disposed at the bottom of the cavity; a first electrode area 6 and a second electrode area 7 included in the metal layer; at least one LED chip 4 disposed on the metal layer, an anode and a cathode of the LED chip 4 being connected with the first electrode area 6 and the second electrode area 7 of the metal layer respectively through gold lines 3; a fluorescent adhesive 2 filled in the cavity of the support 1. The fluorescent adhesive 2 is prepared by mixing fluorescent powder with packaging adhesive in a certain ratio, and the fluorescent powder in the fluorescent adhesive 2 is evenly distributed. When the LED chip emits light, the fluorescent powder absorbs light and is stimulated into various colors.
However, the existing LED packaging structure has the problem of small visual angle. As shown in FIG. 1, the visual angles of the existing LED packaging structures are all about 120°, which limits the irradiation range and irradiation effect of the LED packaging structures. Thus, when the LED packaging structure is used as a backlight source of a liquid crystal display (LCD), it may easily cause glowworm defect of the LCD.
The prior art generally enhances the visual angle of the LED packaging structure through improving the fluorescent powder formulation or improving the material of the support, but these methods are difficult to be developed, have high research and development costs, and are not easy to be implemented.